This invention relates generally to coil inserting equipment and more particularly to a method and apparatus for transferring coil beginning and ending wires or leads from retained positions on a coil insertion blade assembly to restraining devices on a stator pallet and from the stator pallet to a coil lead terminating and finishing apparatus.
In the assembly of a dynamoelectic stator and the insertion of prewound coils into the stator core slots the stator coils are generally wound on a coil form. The beginning and ending coil wires or leads are left to hang loose when the wound coils are transferred from the coil winding form to the coil insertion blades for insertion into the stator core slots. Such coils may have as few as two leads, i.e. a beginning and an ending lead, or a much greater number of leads, depending upon the number of poles, the number of windings, the use of interpole wires and the like.
The coil form on which the coils are wound has several sections of increasingly larger diameter and the first coil is generally wound on the smallest coil form section. Coils of increasing size are then wound in succession on the increasingly larger diameter sections. The completed wound coils are stripped from the coil form onto a circular array of insertion blades and are held loosely thereon for insertion by a coil stripper into the stator core together with insulation wedges. The stator core may be held in a stator core carrying pallet during this process. After insertion of the first set of coils into the core additional coils may be wound and inserted into the core if the motor requires more than one winding. When all the coils have been inserted into the stator core, finishing operations are performed on the stator such as drifting and lacing operations.
In prior art coil insertion methods and equipment the coil leads have normally been left hanging loose throughout the coil inserting and finishing operations so that the coil leads must be located and identified prior to performing finishing operations on the leads such as for instance trimming, insulation stripping, and terminal connecting operations. The process for locating and identifying the coil leads for performing the finishing operations thereon has, in prior art processes and equipment, been performed manually which is a cumbersome and time consuming operation. It is therefore desired to provide a method and apparatus for identifying, positioning, retaining and transferring coil leads during the assembly of a stator, whereby the stator coil leads are identified and releasably retained throughout the entire stator assembly process.
Another problem which has been encountered with prior art coil assembly methods and equipment has been that the loose coil leads, during insertion of the coils into the stator core, tend to get caught or tangled in the end turns of the coils or to be caught between successive coil layers, thereby making it necessary to manually locate and extricate the coil leads prior to performing the finishing operations thereon. Additionally, the leads tend to become damaged or broken off during the processing of the stator thereby resulting in defective motors. It is therefore desired to provide a method and apparatus for assembling a stator wherein the coil leads are retained or restrained in retaining devices during assembly of the coils into the stator core whereby the leads are not subject to being caught or entangled in the coils during coil insertion and processing of the stator and being damaged or broken off thereby.
A further problem which has been encountered in the assembly of stator coils into stator cores has been that the leads are not identified throughout the assembly process. Therefore when a finishing operation on the leads is to take place the leads must not only be located but must also be identified to insure that proper circuit connections will be made to the leads. This requires additional time during the assembly process and furthermore is subject to errors on the part of the operator thereby resulting in defective motors. It is therefore desired to provide an apparatus and method for assembling coils into stator cores whereby the coil leads are identified throughout the assembly process thereby reducing the possibility of operator error and the number of defective motors.
Still another problem which has been encountered with prior art methods and equipment for fabricating stators is that, as the stator pallets are being transferred from one operating station to the next on a transfer conveyor, the loose leads tend to get caught in the conveyor mechanism and therefore tend to be damaged or even cut off. It is therefore desired to provide a stator assembly method and apparatus to position the coil leads in retaining devices which are part of the stator carrying pallet during the entire stator assembly process.
A still further problem which has been encountered with prior art stator assembly processes is that partially assembled stators could not be tested since the stator coil leads were not identified and available for testing without manual intervention until the stator has been completely assembled. It is therefore desired to provide a method and apparatus to locate and identify stator coil leads whereby testing of stators can be accomplished throughout the entire stator assembly process.